Handle new Boot Camp ESDs that use AutoUnattend.xml

[timsutton]

As of yesterday, two new ESD updates now offer two different installers for a large cross-section of Mac models, which use a special tag in the dist file: BootCampAutoUnattend

These work by executing the setup.exe as a FirstLogonAction, but the actual installation is still manually initiated.

Very preliminary testing seems to show that these unattend versions can still be installed silently using the msiexec command we already use.

One solution would probably be to simply prefer the BootCampAutoUnattend tag if it exists, but some further testing should be done to determine what scenario Boot Camp Assistant will pull one or the other.

Currently, the iMac13,3 (a 3TB-equipped iMac with special EFI code to support exposing GPT to Windows??) is a previously-unlisted-in-ESDs model that's only available the AutoUnattend driver version.

A temporary solution to prevent it from breaking on all other models has been pushed in version 0.1.3, which simply skips any dist found with a BootCampAutoUnattend tag.

[timsutton]

It's been posted here that the iMac13,3 is the new 'eMac' iMac.